The present invention relates generally to the field of controlling a railway consist and more specifically to the field of generating and tracking optimal consist driving profiles.
In freight train and other railway consist operations, fuel consumption constitutes a major operating cost to railroads and is also the ultimate source of any potentially harmful emissions. Reducing fuel consumption, therefore, directly increases railroad profit and directly reduces emissions. While modest fuel savings are possible by improving efficiencies of engines and other components in the locomotive propulsion chain, larger savings are generally expected to be achieved by improving strategies for how the train is driven. A train driving strategy specifying throttle or brake settings or desired consist speed as a function of distance along a route or as a function of time is referred to as a “driving plan”.
Train schedules are determined by a central dispatcher and are frequently changed, to account for variability from numerous sources, often as a train is en route to a next decision point. At heavy traffic times, the schedule may have no schedule slack time and can only be met by continuous operation at prevailing railroad speed limits.
Frequently, however, the schedule does have at least some schedule slack time, allowing the engineer to drive at average speeds well below the speed limits and still arrive at subsequent decision points on time. Under such circumstances, it is possible to calculate an optimal driving plan that exploits the schedule slack time and minimizes fuel consumption, or an alternative objective function, subject to constraints of meeting the schedule and obeying the speed limits.
Opportunities exist, therefore, to provide train drivers with tools for generating driving plans and controlling railway consists to exploit schedule slack time and improve railway consist efficiency and performance.